Measuring for replacement of rotted roof sheathing
Hi all,
I’m replacing the roof on an old garage with 2×4 rafters & 1×6 sheathing. An area of the roof had become home to carpenter ants, and so must be replaced. I plan to use 3/4″ plywood. Nothing is ever straight or square, so I need to measure carefully to cut a piece that fits well, roughly 7’6″ x 6′. To measure, I plan to measure edge to edge to get the perimeter dimensions, then measure the diagonals by putting nails in two adjacent corners of the area for the tape’s hook then measure to the opposite corner. For layout, I would then draw 2 opposite edges, then mark the distance from one corner to where the diagonal dimension intersects the opposite edge to make the opposite corner. From the corners and the perimeter dimensions I should get an accurate recreation, regardless of how out of square the area is. Can anyone suggest a better way?
Thanks,
Scott
Replies
scott
The only way I use to get a bastard shape to come out right is to layout off two lines, that are square to each other. All perimeter dimensions come off those two lines. It doesn't make any difference where these square to themselves lines are placed.
or, forget about plotting lines-it's roof sheeting.............
Cut your ply a bit large for the area to be covered.
Take it up there and register a long straight edge to the old sheathing, overlapping the area to be cut on the other 3 sides..
Tack it down at the perimeter of the other 3 sides.
Transfer the cut lines below to the sheet above.
Set your saw depth to make it just through the sheet. Cut to the 3 lines your transfered, ply drops down right into the space you want to fill.
Nail it off.
The only nails you might hit while cutting are under the overcut-remove those from the old sheathing b/4 you perform this operation.
Why not just use 1 x 6 planks for replacement?
Measuring for replacement of rotted roof sheathing
Mostly time. the local lumber yard does not sell shiplap 1 x 6's and ripping a 3/8" square off each edge would just take too long. I've not priced it out, but I'm sure the 1 x 6's would cost more as well.